<template>
  <div class="app-container">

    <!-- 在这里放一个 Header  -->
    <mt-header fixed title="黑马程序员·Vue项目">
      <span slot="left" @click="goBack" v-show="flag">
        <mt-button icon="back">返回</mt-button>
      </span>
    </mt-header>

    <!-- 路由的容器坑 -->
    <transition>
      <router-view></router-view>
    </transition>


    <!-- tabbar区域 -->
    <nav class="mui-bar mui-bar-tab">
			<router-link class="my-tab-item" to="/home">
				<span class="mui-icon mui-icon-home"></span>
				<span class="mui-tab-label">首页</span>
			</router-link>
			<router-link class="my-tab-item" to="/member">
				<span class="mui-icon mui-icon-contact"></span>
				<span class="mui-tab-label">会员</span>
			</router-link>
			<router-link class="my-tab-item" to="/shopcar">
				<span class="mui-icon mui-icon-extra mui-icon-extra-cart"><span class="mui-badge">{{ totalcount }}</span></span>
				<span class="mui-tab-label">购物车</span>
			</router-link>
			<router-link class="my-tab-item" to="/search">
				<span class="mui-icon mui-icon-search"></span>
				<span class="mui-tab-label">搜索</span>
			</router-link>
		</nav>

  </div>
</template>


<script>
import { mapGetters } from 'vuex'

export default {
  data(){
    return {
      flag: true //默认显示返回按钮
    }
  },
  methods:{
    goBack(){
      // 点击返回
      this.$router.go(-1)
    }
  },
  created() {
    if(this.$route.path === '/home'){
      this.flag = false
    } else {
        this.flag = true
    }
  },
  watch: {
    // 当页面刷新的时候，不会触发 watch 里的监听对象
    "$route.path": function(newVal,oldVal){
      if(newVal === '/home'){
        this.flag = false
      } else {
        this.flag = true
      }
    }
  },
  computed: {
    ...mapGetters(["totalcount"])
  }
  
}
</script>

// 这里写的样式，要符合 scss 语法，并且，样式是 当前组件私有的，不会成为全局的样式，也不会应用给子组件
<style lang="scss" scoped>
.app-container {
  padding-top: 40px;
  // 当组件进行切换的时候，一瞬间，页面的宽度会变成正常宽度的2倍，此时需要隐藏品目外的区域
  overflow: hidden;
}

// 动画效果相关的类样式
.v-enter{
  opacity: 0;
  // 让即将进入的页面，向右偏移 100%
  transform: translateX(100%);
}
.v-leave-to{
  position: absolute;
  opacity: 0;
  transform: translateX(-100%);

}

  .v-enter-active,
  .v-leave-active{
    transition: all .4s ease
  }

  mint-header {
    z-index: 99;
  }
.mui-bar-tab .my-tab-item.mui-active {
    color: #007aff;
}

.mui-bar-tab .my-tab-item {
  display: table-cell;
  overflow: hidden;
  width: 1%;
  height: 50px;
  text-align: center;
  vertical-align: middle;
  white-space: nowrap;
  text-overflow: ellipsis;
  color: #929292;
}

.mui-bar-tab .my-tab-item .mui-icon {
    top: 3px;
    width: 24px;
    height: 24px;
    padding-top: 0;
    padding-bottom: 0;
}

.mui-bar-tab .my-tab-item .mui-icon~.mui-tab-label {
    font-size: 11px;
    display: block;
    overflow: hidden;
    text-overflow: ellipsis;
}
</style>